Answer:
a. Brain
Explanation:
The Central Nervous System (CNS) includes the brain and spinal cord. The brain is made up of 3 main parts, known as the cerebrum, cerebellum, and brainstem. The spinal cord is made up of 5 sections, known as the cervical, thoracic, lumbar, sacral, and coccygeal.
Learn more about the Central Nervous System, here:
https://brainly.com/question/29775561 - See rafikiedu08's answer.
~
